Operating mechanism for circuit breakers



July 29, 1930. D. RNNBERG Er AL l1,771,421

OPERATING MECHANISM FOR CIRCUIT BREAKERS Filed Sept. 24, 1929 i do MDM gw f www m w new Tf a yPatented July y29, 1930 1 eures l?.are1511"l orrlcii'fv DANIEL RNNBERG AND Miou @vom or LUDvlxa, SWEDEN. @smears r9 ear-.-

HANNA RAMON 0F SWEPEN n SvENSKe vermisse. eKU-IEBL-em; .er mams, SWEDEN.; a were# ornamme MECHANISM ron CIRCUIT Biesemans Application led September 24, 1929, Serial No. 394,775, and. in Sweden September 26, 1928.

The present invention relates to operating mechanism for circuit-breakers of the type in which a spring is compressed by hand or by means of a motor and closes the circuitbreaker in being expanded. The opening of the circuit-breaker is on the contrary effected by so-called free release, independent of the closing mechanism. In the devices of this kind hithertor used, the spring has been connected to the driving mechanism by an arrangement which is disconnected at the closing operation so that only the spring, the circuit-breaker contacts and the intermediate members have been in motion on this occasion. This has however frequently been found to cause the inconvenience of too hard a shock at the closing operation which may cause the risk of damaging the contacts.

According to the present invention, the spring is permanently connected withy the mechanism for its compression, said mechanism comprising among other members a helical gearing having a pitch angle greater than the friction angle so as not to be selflocking. This gearing is thus brought in motion by the spring during the closing operation so as to exert a damping action on the shock which otherwise would occur. Other items of the invention will appear in the following detailed description thereof.

A form of the invention is illustrated in theaccompanying drawing where Fig. 1 shows the same in a side view, partially in section, in the position corresponding to closed circuit-breaker, some of the parts being shown in dash anddotted lines in an-l other position. Fig. 2 shows the principal mechanism according to Fig. 1 in a corresponding view, with the parts in the Lstate ready for closing the circuit-breaker.

lThe spring 1 is by means of a lever 2 movable on a pivot 3 connected with the mechanism for o erating the circuit-breaker contacts and wlth a crank mechanism consisting of a link 5 and a crank 6. The latter is mounted on the same shaft kas a gear wheel 7 in which engages a screw 8. The pitch angle of the screw is larger than the angle viS then expanded" and c .16. which is guided in a of friction so kthat the gearing will not v gearing iS www b3' e? fOPr'te driving meenfforiestance a Cra. 9S@ es to can@ the gear wheel 7 to rotate in the direction of the arrow from ytheposition shownin Fig'. 1 to that ,shown in Fig. 2. i In the latter position, in'which the crank has movda little over its point, itis th/e lockedl for instance by means of ay devicedescribedbelow if the circuit-breaker` shallnotbe closed at onceT When the closing shall'be leffected'the gear wheel is allowedto continuehits move# ment in thedirectioxiiof arrow'to about the position shown in F ig.A 1.V The. spring n cha circuit# breaker, the motive ofthe vrxwhail,Sraheilig retarded bythe caring 'soas not to cause a too heavyshoc atthe contacts. `The mechanism for o y.erating'the circuit.'- breaker contacts from t e lever 2,ncludin` the mechanism for freerelfea'se ofthe said contacts, in the form shownl comprises'tlie following parts. The link 5 ha ll extens1on whichisconnected toa4 double near the centre thereof. One end ofwhis lever 1s by means kof a rod 4 copnectv to ahethr 1e`ve1723 which yil'ilfs mais Cennected, b means ,Ofen insulating fregi '24,f`to

the mova y le contacts of ythe circuit-breaker. The other end of the leverl' carries a groove 17 in the stationary frame 18 of/.the ap aratps. Further it has a projection 19W ich'is caught Aby a correspondmg `'projectibn on a hellcrank lever 2Q and can be releasedbyfmeans of afstud forming themovahle part. Qf a relay' When thek bell-crank lever iis rleased 1in this Way, the end ofthe 1ever'13 carryme' 'the -stufdf 16 is moved dwnwrds `along thev groove 17,;and the circuitfbneafker is t en yopened notwithstandin l that vthe crank 6 and link 5 still occupy teirclosin position. Theposition" of the lever 13 'and detsd. linee in Fig- 1- bis " The, serra! .Sie 'Prefrbly sentaba# di directi placed inits longitudina n and 'connected to two disengaging couplings l0, 11. The coupling 10 which is engaged when the screw is moved to the left in the drawing connects it to the driving means 9 while the coupling l1 which is engaged at a displacement in the opposite direction connects the screw either to a fixed part or to a disc or the like influenced by a brake. During the movement for compressing the spring l, when the tooth pressure from the gear wheel acts on the screw towards the left, the coupling 10 is kept in engagement so that the screw is connected to the driving means 9. Vhen the crank mechanism 5, 6 passes its top point, the direct-ion of the tooth pressure is reversed whereby the coupling is disengaged and the coupling l1 instead engaged, so that the gearing 6 stops inthe position shown in Fig. 2. ln order to release the spring and ythus close the circuit-breaker, the coupling 1l can then be disengaged by means of a hand lever l2.

We claim as our invention:

1. Operating mechanism for circuit-breakers comprising movable contacts, a compressible spring, means connecting together said contacts and spring so as toclose the contacts on the expansion of the spring, and means for compressing the spring comprising a helical gearing permanently connected to said spring and having its pitch angle greater than the angle of friction.

Q. Operating mechanism for circuit-breakers comprising movable contacts, a compressible spring, means connecting together said contacts and spring so as to close the contacts on the expansion of the spring, and means for compressing the spring comprising a crank mechanism and a helical gearing having its pitch angle greater than the angle of friction and connected to said spring by said crank mechanism.

3. Operating mechanism for circuit-breakers comprising movable contacts, a compressible spring, means connecting together said contacts and spring so as to close the contacts on the expansion of the spring, means for compressing the spring comprising a crank mechanism, a helical gear wheel having its pitch angle greater than the angle of friction, a screw engaging said wheel and displaceable in its longitudinal direction under the gear pressure and a coupling connecting said screw to driving means when displaced in oneY direction, and another` coupling connecting said screw to stopping means when displaced in the opposite direction.

4. Operating mechanism for circuit-break ers comprising movable contacts, a compressible spring, means connecting together said contactsand spring so as to close the contacts on the expansion of the spring, means for compressing the spring comprising a crank mechanism, a helical gear wheel hav- 

